I think that people who are not willing to switch roles are kind of selfish. For me, its one thing if you are a sub, and you love it, and you luck up and find someone who is a dom and you guys are both perfect matches. But It is my opinion that most relationships are give and take. And if your partner is willing to sacrifice their likes/dislikes to satisfy you, you should be willing to that for them (If thats what they wan).

So to answer your question, I would definetly say for me, being a switch was something that I learned. I am easily more submissive. But I think its easier to talk to people if you can switch. And then you are in a better position to say, "Hey Look..its my turn to kneel now lol